You’re probably too young to remember “War of the Worlds.” Before you try to protest, I’m not talking about the one with Tom Cruise. We’re all just going to continue pretending that never happened. “What never happened?” you ask. And that’s good. Because nothing did.

No, there was only one War of the Worlds, and that was the one that was enacted over radio (remember that?) in 1938 on a show called Mercury Theatre on the Air. It was the story of a Martian attack, the first two thirds of which were told in the format of news bulletins. As you’ve probably heard, some degree of hysteria followed as listeners tuning in didn’t quite catch on to the fact that it was simply a radio drama.

Enter Z-Day.

Z-Day is a massive, real-time social experiment – like War of the Worlds meets Balloon Boy meets #IranElection.

On October 30th, 2009, dedicated Zombiephiles on Twitter will simulate a zombie outbreak, tagging their zombie-related tweets with the #zday hashtag. The resulting real-time stream of tweets will be known as Z-Day and will be remembered by zombiephiles around the world for centuries to come (or, more likely, about a week or so). We’ll be tracking those Z-Day tweets in real time at our special Z-Day website which launched today.

Want in on the action? It’s simple. If you’re not already using Twitter, you can sign up quickly and easily (and for free!) at Twitter. Once you’ve done that, you can either use the Twitter website or download a Twitter client like Seesmic Desktop or Tweetdeck to view tweets and send out your own.

Z-Day has no rules, just two simple steps necessary to make it work:

Tweet as if a zombie outbreak has begun.

Mark your tweets with the #zday hashtag.

Other than that, it’s entirely up to you. You want fast zombies? Tweet about fast zombies. You want slow zombies? Tweet about slow zombies. Radioactive comets causing the zombie outbreak? Tweet your suspicions. Suspect it might be transmitted by bite? Tweet that. The power to shape Z-Day is entirely in the hands of us, the Zombiephiles, and we’re going to make it a day to remember for zombie fans around the world.